Amplification on a solid phase consists of the elongation, during a PCR reaction or other types of amplification, such as LCR, SDA, etc., of a primer which is prebound to a solid support. Such a technique makes it possible to obtain an amplification product one specific strand of which is covalently attached to the solid phase, without using any steps other than PCR. This makes it possible to carry out detection before denaturation on double-stranded DNA, or after denaturation on a specific strand of the amplification product by combining PCR and detection without changing support.
Methods for the solid-phase amplification of nucleic acids have been described in WO 89/11546, AU 47144/89 and WO 93/09250.
This type of amplification on a support may be very useful for all the molecular biology diagnostic applications, in particular for detecting infectious targets or genomic targets. This technique makes it possible to reduce detection times as well as the risks of errors, since the sample is not transferred from one well to another but the entire experiment takes place on the same support. Moreover, for all the applications requiring only a single specific DNA strand, such as cloning or sequencing, this technique may allow a real saving in time and great ease of use avoiding many intermediate steps.
The primer involved in the PCR, which is bound at its 5' end to the solid support, must form part of the strand which it is desired to elongate on the solid support. The 3' end of the primer must be free, unmodified and homologous with the target, in order to allow its elongation by a polymerase.
However, a major drawback of solid-phase amplification is the low yield of elongation on the solid phase.